Ice Trolls is a short essay included as part of the Troll Compendium (via a link named "Ice Trolls") on the old official site that describes this particular sub-species of troll. It is reproduced here, in case the archive of the page disappears.

Contents

Historians and physicians generally classify trolls into four categories: forest trolls, jungle trolls, ice trolls, and sand trolls. The trolls of the Zandalar tribe are considered unclassifiable because the Zandalari are the earliest known trolls, from whom all other trolls are descended.

There is some debate as to how many categories are necessary in order to describe the troll race. Several notable authorities on the topic have chosen to specify a fifth category: namely, the dark trolls.

Description: The skin of ice trolls can range from white to blue in color. A few green-skinned ice trolls have also been observed, but they are very rare, for such cases are matters of pigmentation alone (not plant growth, as with the forest trolls). Ice trolls typically have thick manes of hair.

Ice trolls are particularly savage and cruel, even by troll standards, but these unpleasant traits are not the product of the trolls' snowy territories. Rather, several troll tribes were driven into the far north long ago as a direct result of their behavior, and over time they developed into ice trolls.

History: Like other trolls, ice trolls are descended from the Zandalar tribe, but broke off to form several small tribes of their own. These new tribes proved too bloodthirsty for other races to tolerate. Driven out of civilized lands, the trolls were forced to settle in the far north of ancient Kalimdor, in the region that later become the continent of Northrend. Long before the Great Sundering, these ice trolls founded a small nation known as Zul'Drak, which never achieved the size or prosperity of the two southern empires.

For the most part, ice trolls have had little to do with the so-called civilized world; many of them still dwell in Northrend. Only recently have ice trolls been sighted in significant numbers in the Eastern Kingdoms, where the Frostmane tribe is launching increasingly frequent and aggressive attacks.